The saying Friends don't lie is an old adage that has been around for centuries. It means that friends should be honest with each other, even if it means telling them something they don't want to hear. The saying Friends don't lie is based on the idea that trust is essential for any healthy friendship. If friends can't be honest with each other, then the friendship is built on a foundation of sand. There are many reasons why it is important for friends to be honest with each other. Honesty helps to build trust, which is essential for any close relationship. An Inscription Friends Don't Lie Sticker.